1. Field of the Invention
The invention relates to an integrated flexible optical transducer element. More specifically, the invention relates to such an element having parallel integrated optical waveguide surfaces.
2. Description of Prior Art
Optical sensors are well known in the art and, traditionally, such sensors are formed of optical fibers. A summary of the state of the art having regard to such fiber optic sensors is given in Optical Fiber Sensor Technology, IEEE Journal of Quantum Electronics, Vol. QE-18, No. 4, April 1982, pps. 626 et seq., Giallorenzi et al. This paper discusses the characteristics and advantages, as well as several embodiments and uses, of such sensors. Specific fiber optic arrangements are also taught in Fiber-Optic Sensing of Pressure and Temperature, Applied Optics, Vol. 18, No. 9, May 1, 1979, pps. 1445 et seq., Hocker, and Fiber Optics Strain Gauge, Applied Optics, Vol. 17, No. 18, Sept. 15, 1978, pps. 2867 et seq., Butter et al.
Fiber optic transducers are also taught in U.S. Pat. Nos. 4,408,829, Oct. 11, 1983, Fitzgerald Jr. et al., 4,421,384, Dec. 20, 1983, McMahon, and 4,472,022, Sept. 18, 1984, Bearcroft et al.
Optical waveguide transducers are taught in U.S. Pat. Nos. 4,142,774, Mar. 6, 1979, Wright, and 4,471,474, Sept. 11, 1984, Fields. In the Wright patent, the waveguide extends internally through a flexible member which includes grooves on one surface thereof whereby to produce a periodic strain pattern in the waveguide on flexure of the member. In the Fields patent, waveguides are disposed on the facing, parallel, surfaces of two separate substrates. The substrates are disposed in a flexible housing.
U.S. Pat. Nos. 3,871,742, Mar. 18, 1975, Kaminow et al, 4,445,751, May 1, 1984, Divens et al and "End-Fire Coupling Between Optical Fibers and Stripe Waveguides", First European Conference on Integrated Optics, September 1981, Andonovic et al, teach methods of coupling optical fibers to optical waveguides.